BIO FINAL
In what direction do Okazaki fragments replicate?
5' -> 3'
What is the codon for Methionine?
AUG
Which is true of polypeptide tertiary structure and quaternary structure?
Both structures have specific shapes that depend upon the amino acid sequence of the protein.
Cells contain buffers that help maintain a neutral pH. Which of the following statements is not relevant to how buffers work?
Buffers catalyze oxidation-reduction reactions..
Which of the following is NOT an example of external assault on DNA?
By-products of metabolism
Which association between complementary bases would require the most energy to break?
C-G
Which antibiotic blocks the binding of aminoacyl-tRNA to A-site of prokaryotic ribosomes?
Tetracycline
Select all that apply. One of the two X chromosomes is inactivated in the cells of mammalian females by heterochromatin formation. What would happen if the X-inactivation did not occur?
Women would make double the amount of proteins encoded by the X chromosome and It would cause a genetic disorder such as downs syndrome
In eukaryotes, translation occurs in the _____.
Cytoplasm
Which of the following represents the correct order of enzyme participation in DNA replication?
DNA Helicase > RNA Primases > DNA Polymerase > DNA ligase
When comparing gene transcription and DNA replication, which statement is incorrect?
DNA in polymerized in the 5' to 3' direction, whilst RNA in read in the 3' to 5' direction.
During DNA repair, what enzyme stitches the backbone of DNA, if broken?
DNA ligase
Strong acids, such as hydrochloric acid (HCl), lose their protons ____. Acetic acid, on the other hand, is a weak acid because it holds on to its proton _____ when dissolved in water.
Easily, tightly
In the process of creating eukaryotic polypeptides, polyadenylation plays a critical step. Where does this step occur in the cell?
Nucleus
Which of these, located in eukaryotic cells are enclosed by two membranes?
Nucleus and Mitochondria
What is the most prominent form of DNA damage caused by sun beds?
Pyrimidine dimers
Select all that apply. Eukaryotic cells have several ways to adjust the local structure of their chromatin rapidly through chromatin-remodeling complexes. Protein using covalent modifications such as ___change the position of the DNA wrapped around nucleosomes.
all
Which of the following are forms of membrane proteins associating with the lipid bilayer? [select all that apply. Clue it is more than one!
all
Which of the following is responsible for initiation of RNA polymerase activity in prokaryotes?
Sigma factor
Figure 3-20 is an energy diagram for the reaction X→Y. Which equation below provides the correct calculation for the amount of free-energy change when X is converted to Y?
c - a
Which of the following chemical groups do all amino acids have in common?
carboxyl group
There is incredible diversity in size, shape, environment, and behavior in living systems. There are approximately between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit?
cell
Select the answer that best fits the blank. The __ bind to newly synthesized or partially folded chains and helping them to fold along the most energetically favorable pathway.
chaperone proteins
The energy used by the cell to generate specific biological molecules and highly ordered structures is stored in the form of
chemical bonds.
Which of the following membrane lipids does not contain a fatty acid tail?
cholesterol
Which of the following choices BEST describes the role of the lysosome?
clean-up, recycling, and disposal of macromolecules
mRNAs are designed for what cellular function?
code for proteins
In cells, macromolecules are synthesized by __reactions and broken down by __ reactions
condensation, hydrolysis
Long polymers are made from single subunits in cells using a ___________ reaction, which ___________ water.
condensation; releases
Which of the following covalent bonds would be considered nonpolar?
covalent bond between O and O (O=O)
Ionic bond formed between two atoms is a result of the
donation or acceptance of electrons from the other atom
Acids are characterized as being strong or weak, depending on how
readily they give up their protons to water
Secondary structures of a protein are the....
regular, repeated folds present in a lowest energy conformation.
Where are hydrophobic interactions most likely to occur?
the core of a water-soluble protein
Which genes are transcribed by RNA polymerase III?
-5S rrNa gene -Genes for many other small rNas -trNa genes
What are the method(s) for isolating or separating proteins? Choose all that apply.
-Electrophoresis -Chromatography -Isoelectric focusing
Which of the following are examples of general protein function? Select all that may apply.
-Transport Proteins -Receptor Proteins -Gene Regulatory Proteins
What part of the chromatin fiber does the remodeling complex directly attach to? Select all that apply.
-attaches to histone octamer -attaches to the DNA wrapped around histone octamer
elect all that apply. Which of the following statements are true? [multiple apply]
-competitive inhibitors block enzyme activity by competing directly with the substrate for the enzyme's attention -competitive inhibitors do not change the Vmax of a reaction
What is the purpose of RNA capping and polyadenylation modifications on RNA? Choose all that apply.
-increase the stability of a eukaryotic mRNA molecule, -facilitate its export from the nucleus to the cytoplasm
Nucleosomes are formed when DNA wraps __________ times around the histone octamer in a __________ coil.
1.3; right-handed
How many codons are needed to generate a peptide that is nine amino acids long, assuming one of them is a stop codon?
10
A cell is mutated in such a way that it is no longer able to produce uracil. How many different types of amino acids is this cell still able to produce? Use this chart to help you eliminate options.
12
The inner most shell of an atom can hold __ electrons
2
The human genome is a diploid genome. However, when germ-line cells produce gametes, these specialized cells are haploid. What is the total number of chromosomes found in each of the gametes (egg or sperm) in your body?
23
The leading strand of a DNA molecule has the following sequence: 5'-CGCATGTAGCGA-3'. Which of the following sequences is complementary to the leading strand shown above?
3'-GCGTACATCGCT-5'
If you have a strand of DNA in which 20% of the bases are adenine, what percentage of guanine do you have?
30%
What is the anticodon corresponding to the codon 5'-GUA-3'
5'-UAC-3'
Larger molecules have hydrogen-bonding networks that contribute to specific, high-affinity binding. Smaller molecules such as urea can also form these networks. How many hydrogen bonds can urea (Figure 2-26) form if dissolved in water?
6
How many electrons in the atom's outer shell below? Oxygen, nitrogen, hydrogen, and carbon.
6, 5, 1, and 4.
Knowing the difference between prokaryotic and eukaryotic translation is important. During eukaryotic translation, the large subunit of the ribosome will translocate. Right after this event occurs, which site/sites of the large subunit will now contain a tRNA?
A and P sites
Select all that apply. During a condensation reaction ..
A bond is formed and Water is expelled
What occurs if a cell reproduces by replicating its DNA and then dividing in two, passing a copy of the genetic instructions encoded in its DNA to each of its daughter cells incorrectly?
A mutation.
A mutation is __
A permanent change to the information carried by the DNA molecule
Which of the following is synthesized when a phosphate group is removed from ATP?
ADP
What role does ADP play in this based on the image below?
ADP acts as an allosteric regulator that improves substrate binding
Homologous Recombination Repair (HR or HRR):
All answers are correct
What factors do NOT lead to DNA mutation?
All answers can lead to DNA mutation
Which of the following is NOT part of the cell theory principle?
All cells contain a nucleus
Describe the function of microtubules.
All of the above
Explain why the it is thought that mitochondria are likely evolved from an engulfed prokaryotic cell.
All of the above
Which is (are) necessary for DNA polymerase to perform its function?
All of the answers are correct
Which of the following is (are) possible post-translational modification(s)?
All of the answers are correct
Which of the following are used to distinguish RNA from DNA?
All of these are used to distinguish RNA from DNA
Membrane proteins, like membrane lipids, can move laterally by exchanging positions with other membrane components. Which type of membrane protein is expected to be the least mobile?
Anchors
These organisms may be found in extreme environments such as in the hot acid of volcanic springs.
Archea
__ and __pathways together constitute the cell's metabolism
Catabolic, anabolic
What is the fundamental unit of living matter?
Cells
All are true about the functional relationship between codons and amino acids except?
Codons always code for multiple amino acids.
The synthesis of macromolecules such as proteins, nucleic acids, and polysaccharides require an input of energy. In each case, synthesis involves a _______ reaction in which water is ______.
Condensation, lost
Using a _______ microscope, a beam is focused onto a single point at a specific depth in the specimen, and a pinhole aperture in the detector allows only fluorescence emitted from this same point to be included in the image. Scanning the beam across the specimen generates a sharp image of the plane of focus—an optical section.
Confocal
What is the first mechanism for repairing nucleotide errors in DNA following DNA polymerization?
DNA polymerase proofreading
Which type of reaction creates order in the universe, by having a positive ΔG? How are they able to occur?
Energetically Unfavorable, they take place only when they are coupled to a second reaction with a negative ΔG
The measure of a system's disorder is called the ______ of the system, and the greater the disorder, the greater the entropy
Entropy
If a cell is in an environment with elevated glucose levels, and lactose is also present, what would be the expression level of the Lac genes? Use the column method and logic!
Expression under 20%
What is the difference between a fluorescence microscope (FM) and a light microscope (LM)?
FM uses two sets of filters to isolate excitation and emission wavelengths of light
Which of the following monomer building blocks is necessary to assemble selectively permeable boundaries around and inside cells?
Fatty acids
Which specific motor protein generates the forces responsible for muscle contraction and most other eukaryotic cell movements? They also power the intracellular movements of organelles and macromolecules. For example, they help move chromosomes to opposite ends of the cell during mitosis
GTP
Study the image of comparative gene expression below. The WT points represent gene expression levels in a normal (wildtype) organism, whilst the Mut points represent gene expression levels in a mutant organism. Which statement is false?
Gene 2 is expressed at intermediate levels
A ____ is often defined as a segment of DNA that contains the instructions for making a particular protein or RNA molecule. The total genetic information carried by all the chromosomes in a cell or organism constitutes its _____.
Gene, Genome
Which of the proteins below are expressed in all cells?
Glycolytic enzymes
The organelle shown in the figure is the ___________ and one of its main functions is to ___________.
Golgi apparatus; package and modify proteins for secretion
Which interaction is most important in enhancing the solubility of macromolecules in water?
H bonds
Most eukaryotic cells only express 20-30% of the genes they possess. The formation of heterochromatin maintains the other genes in a transcriptionally silent (unexpressed) state. Which histone modification is associated with the formation of the most common type of heterochromatin?
H3 lysine 9 methylation
The presence of just an activated activator complex and the appropriate polymerase enzyme at the promoter, the bacterial lac operon will yield:
High gene expression
What force normally holds the two strands of DNA together?
Hydrogen Bonding
In response to starvation, what gland releases the hormone Cortisol?
Hypothalamus
One of the processes making proteins in a Eukaryotic cells, mRNA degradation will sometimes occur. Where does this even usually take place?
In the cytosol
_____ bonds are usually formed between atoms that can attain a completely filled outer shell most easily by donating electrons to—or accepting electrons from another atom, rather than by sharing them
Ionic
Why is carbon-12 a stable isotope?
It has the same number of protons and neutrons
Select all that apply. Which of the following is true regarding endocytosis?
It helps intake bulk materials into the cell and Is a form of active transport
The Shine-Delgano sequence present in bacterial mRNA is essential for the initiation of translation because:
It is complementary to an RNA sequence in the small ribosomal subunit
You find that a molecule has many charged groups that can cross a cell's membrane. How do you think it crosses the cell membrane?
It may be transported by some transporter.
The study of enzymes also includes an examination of how the activity is regulated. Molecules that can act as competitive inhibitors for a specific reaction are often similar in shape and size to the enzyme's substrate. Which variable or variables used to describe enzyme activity will remain the same in the presence and absence of a competitive inhibitor?
Km
Which one statement is correct about the ribosome structure of prokaryotes?
Large subunit contains 5s and 23 rRNA and 34 proteins
In the early stages of a bacterial infection, the carbohydrate on the surface of white blood cells called neutrophils is recognized by a _________ on the cells lining the blood vessels at the site of infection; this recognition causes the neutrophils to adhere to the blood vessel wall and then migrate from the bloodstream into the infected tissue, where they help destroy the invading bacteria
Lectin
What characteristics would make the lipid bilayer the least fluid?
Long fatty acids tails and high amount of cholesterol
Which one represents the role of RNA polymerase I?
Making RNA of ribosomes
What are the 3 most common histone modifications?
Methylation, Phosphorylation, Acetylation
Generally, you would use the unit of _____ to measure a typical plant or animal cell?
Micrometers
This organelle is thought to have evolved from aerobic bacteria that took to living inside the anaerobic ancestors to today's eukaryotic cells.
Mitochondria
How many origins of replication do humans chromosomes have?
More than four
A polypeptide always has an amino _____ group at one end—its N-terminus—and a carboxyl _____ group at its other end—its C-terminus
NH2, COOH
Someone you know has developed a mutation that leads to skin cancer and is pregnant. They are worried that their child will be born with the cancer mutation they have while carrying the baby. Should they be worried?
No, the mutations causing the cancer are in somatic cells, not reproductive germ cells.
With regard to process of splicing, which one statement is false?
Noncoding regions are removed from DNA and coding regions are kept
Select all that apply. Which of the following is not an activated for of the carrier?
None of the above
Covalent bonds in macromolecules are primarily important for, [think through what you know for sure!]
None of these answers
What does RNA polymerase do in prokaryotic DNA replication?
None of these answers
Genome size does not precisely determine gene number, as illustrated in the table. What is a plausible explanation as to why A. thaliana, a plant, has a similarly sized genome as the fruit fly, but twice the number of protein-coding genes?
None of these.
What is the covalent bond formed between the resulting amino acids called?
Peptide bond
Select all that apply. Which of the following organisms can chloroplast be found in?
Plants and Algae
Which atomic particles contribute to the atomic number for every element?
Protons
During transcription, which of the following is produced in prokaryotes?
RNA
Which ONE of the following statements is correct?
RNA molecules are sometimes translated to another type of polymer called a protein
The synthesis of mRNA is catalyzed by the enzyme_____.
RNA polymerase
Which one process is different from others, in terms of the location of gene expression control?
RNA processing control
Which of the following reactions in cells are catalyzed by Ribozymes?
RNA splicing
You obtain the following for Strain A (blue dot A). Which of the locations in red would correspond to your level of expression for the mutant strain B?
Red dot 1
Replication of DNA is fully concluded by which phase of the cell cycle?
S
DNA replication takes place during which phase of an eukaryotic cell cyle?
S phase
Consider this evolutionary tree and then select the one statement which is correct. Scientists study model organisms within these groups to gain insight into these types of organisms and their genetic heritage.
Saccharomyces cerevisiae do not contain chloroplasts.
During prokaryotic transcription, which one of these answer choices is the first to occur?
Sigma factor subunit binds to RNA polymerase to form a RNA polymerase holoenzyme
Which of the following would be most likely to occur if introns were not spliced out of the RNA ?
The RNA would be translated into a nonfunctional protein
The Cdc2 gene identified from the yeast Schizosaccharomyces pombe was found to play a part in multiple events in the cell division cycle. What would likely happen to the S. pombe if a mutation inactivated the Cdc2 gene?
The S. pombe would be unable to divide properly
Which of the following statements about the carbohydrate coating of the cell surface is FALSE?
The arrangement of the oligosaccharide side chains is highly ordered, much like the peptide bonds of a polypeptide chain.
The Cdc2 gene identified from the yeast Schizosaccharomyces pombe was found to play a part in multiple events in the cell division cycle. In the event that a gene was inactivated by a mutation, what would happen if the defective cells were provided with a normal copy of the gene?
The cells would regain their function to reproduce
Scientists learned that cell death is a normal and even important part of life by studying the development of the nematode worm C. elegans. What was the most important feature of C. elegans for the study of programmed cell death?
The developmental pathway of each cell in the adult worm was known.
Why is the oxidation of NADPH energetically favorable?
The oxidized form, NADP+, is more stable than the reduced form NADPH
To study how proteins fold, scientists must be able to purify the protein of interest, use solvents to denature the folded protein, and observe the process of refolding at successive time points. What is the effect of the solvents used in the denaturation process?
The solvents break all noncovalent interactions.
Select all that apply & think it through. Which statement is true of hydrophobic molecules?
They form few or no hydrogen bonds. They are generally uncharged. They are typically hydrocarbons.
Hydrophobic molecules, by contrast, are insoluble in water because all or almost all of their atoms are uncharged and nonpolar; they, therefore, cannot form favorable interactions with water molecules.
True
Which nucleotide sequences represent stop codons? Select all that apply.
UAG,UAA,UGA
In Non-homologous End Joining (NHEJ):
Unlike Homologous recombination, only one DNA helix is available
If torn, membranes will undergo spontaneous rearrangement. Which of the following would happen if a cell membrane underwent a large tear?
Vessicles form
Which of the following characteristics are observed in prokaryotes?
a cell wall and the ability to divide rapidly
Prokaryotic cells do not possess
a nucleus.
A proton in water is ______________ by a base.
accepted
The smallest particle of an element that still retains its distinctive chemical properties is an _____.
atom
Why do sugars tend to be highly water soluble?
because of their large numbers of hydroxyl groups
Louis Pasteur
demonstrated that orgnisms are generated only from existing organism
Two identical, folded polypeptide chains form a symmetrical complex of two protein subunits called a _____ that is held together by interactions between two identical binding sites
dimer
Extracellular proteins are often stabilized by covalent cross-linkages. The most common covalent cross-linkage is ______.
disulfide bonds
Cells that are specialized for the secretion of proteins are likely to have which of the following features?
enlarged endoplasmic reticulum
Yeast is a ______ cell. Select all that apply,
eukaryotic and fungi
Robert Hooke
first to observe cells in a piece of cork through a magnifying lens in 1665
Many motor proteins generate directional movement by using the ___ of a tightly bound ATP molecule to drive an orderly series of conformational changes
hydrolysis
Proteins bind selectively to small-molecule targets called ligands. The selection of one ligand out of a mixture of possible ligands depends on the number of weak, noncovalent interactions in the protein's ligand-binding site. Where is the binding site typically located in the protein structure?
inside a cavity on the protein surface
Double covalent bonds are both shorter and stronger than single covalent bonds, but they also limit the geometry of the molecule because they
limit the rotation of the bonded atoms.
The ___ histone, called histone H1, pulls adjacent nucleosomes together into a regular repeating array and changes the path the DNA takes as it exits the nucleosome core, allowing it to form a more condensed chromatin fiber.
linker
fatty acid
membrane lipids
The cytoskeleton provides support, structure, motility, and organization, and it forms tracks to direct organelle and vesicle transport. Which of the cytoskeletal elements listed below is the thickest?
microtubules
Which of the following feedback loops best describes this image shown below?
negative feedback
There are 20100 different possible sequence combinations for a protein chain with 100 amino acids. In addition to the amino acid sequence of the protein, what other factors INCREASE the potential for diversity in these protein macromolecules?
noncovalent interactions sampled as protein folds
Which of the following methods used to study proteins is limited to proteins with a molecular mass of 50 kD or less?
nuclear magnetic resonance
nucleotides
nucleic acids
The endothelial cells found closest to the site of an infection, express proteins called lectins. Each lectin binds to a particular __________ that is presented on the surface of a target cell.
oligosaccharide
Antoni van Leeuwenhoek
one of the first to observe living cells
Unlike what occurs when fuel is burned to make a fire, all living systems use the energy from heat-generating reactions to create and maintain
order.
They are typically hydrocarbons.
phosphoanhydride
sugar
polyssaccharides
The four histones that make up the octamer are proteins, with a high proportion of ___ amino acids, which help the histones bind tightly to the ___ sugar-phosphate backbone of DNA
positively charged, negatively charged
What type of macromolecule helps package DNA in eukaryotic chromosomes?
proteins
amino acids
proteins
Why is saccharomyces cerevisiae, the same microorganism that is used for brewing beer and baking bread, so advantageous for studying basic mechanisms in eukaryotic cells?
saccharomyces cerevisiae is closely related to plants as it is to animals and reproduces rapidly
An intron is a,
segment of DNA that does not code for proteins
There is incredible chemical diversity even in the simplest of cells. A typical bacterial cell contains more than 6000 different types of molecules. From the list below, select the class of molecules with the largest number of different types.
sugars and precursors
Which part of RNA Polymerase plays a pivotal role in post-transcriptional modification in Eukaryotes?
the tail
Materials are moved from one organelle to another by this cell component.
transport vesicles.
Which of the following is not a DNA nucleic acid base?
uracil
Which of the following is not a base found in DNA?
uracil (U)
The process of sorting human chromosome pairs by size and morphology is called karyotyping. A modern method employed for karyotyping is called chromosome painting. How are individual chromosomes "painted"?
using fluorescent DNA molecules
What kind of noncovalent interaction is shown by interactions between two molecules that are so close together that they can experience weak attractive forces bonding them together?
van der Waals forces
A transmembrane polypeptide chain usually crosses the lipid bilayer as an
α-helix
